What critical event took place during the summer of 1776 in Philadelphia?

The critical event that took place during the summer of 1776 in Philadelphia was the signing of the Declaration of Independence. This document, drafted primarily by Thomas Jefferson, was a significant turning point in American history as it formally declared the thirteen colonies' intentions to separate from British rule. The Declaration articulated the colonies' grievances against King George III and expressed Enlightenment ideals about individual rights, government by consent, and the pursuit of life, liberty, and happiness.

The event was not just about the signing itself but was part of a broader movement toward the establishment of the United States as a sovereign nation. This act of declaring independence was a bold statement of the colonies' resolve to seek self-governance and a radical shift in political thought and practice.

The other events mentioned, such as the ratification of the Constitution and the drafting of the Articles of Confederation, occurred later in the development of the United States' government structure, while the First Continental Congress was an earlier event focused on colonial unity and resistance to British policies, prior to the push for independence.